Created attachment 27008 [details] full output of failed run When running valgrind on Python 2.6 from SVN (r65995), I got the error below (see attachment for full details). valgrind: m_scheduler/scheduler.c:1110 (vgPlain_scheduler): the 'impossible' hap pened. valgrind: VG_(scheduler), phase 3: run_innerloop detected host state invariant f ailure report_and_quit (m_libcassert.c:140) vgPlain_assert_fail (m_libcassert.c:200) vgPlain_scheduler (scheduler.c:1108) run_a_thread_NORETURN (syswrap-linux.c:89) sched status: running_tid=1 Full command line I was using at the time: valgrind -q --leak-check=yes --suppressions=Misc/valgrind-python.supp ./python -E -tt ./Lib/test/regrtest.py -uall,-bsddb,-compiler -x test_logging test_ssl test_multiprocessing I had run valgrind at least twice on nearly the same code and many more times on different test inputs without this problem. Where valgrind failed, there shouldn't have been any active threads. I restarted with the same binary and command line and valgrind passed the place where the problem occurred (ie, I probably can't reproduce this). More system info: $ uname -a Linux janus 2.6.17-12-generic #2 SMP Tue Feb 12 00:40:49 UTC 2008 x86_64 GNU/Linux $ gcc --version gcc (GCC) 4.1.2 20060928 (prerelease) (Ubuntu 4.1.1-13ubuntu5) $ cat /etc/issue Ubuntu 6.10 \n \l
It's a kernel bug. Caused some entertainment the first time we saw it. *** This bug has been marked as a duplicate of bug 143888 ***